Hi,

first, I am glad that you were sent to have some respiratory tests done.

performance of respiratory tests in neuromuscular disorders is not trivial. it is quite easy to see that something is wrong, but assesing the true severity of the respiratory involvement, requires expertise.

I do not have this expertise, and my knowledge regarding this, is purely from my own experience and some reading that I have done, but very far from being able to asess the results of someone else's tests.

MG is very tricky, and you can easily have near normal tests now, and significantly abnormal ones a few hours later. my VC (which is vital capacity), could go from 4.5 to 1.5 and lower, within hours. I probably have more extreme fluctuations then most, but still, I believe that other patients have some changes as well.

also, I have noticed that my pulmonary pressures (which were not measured in your tests) were always much lower then what I expected them to be, sometimes on the verge of intubation, at the same time my volumes were near normal, which made no sense unless I was able to defy the laws of physics.

I eventually found the explanation for this-first, they always measured my volumes and then my pressures, and when we reversed the order the results were quite different. second-they over estimated the weakness of my diaphragm and underestimated the weakness of my other respiratory muscles, and therefore the resistance of my rib cage, was quite low and I was able to produce pretty good volumes with very low pressures, or as my pulmonologist said-your resistance is so low, that I can just go one Poof and easily fill your lungs with air.

he was the first one that actually measured the true pressures that I require, and adjusted my respiratory accordingly, after a year! in which I constantly told everyone that I am not anxious or depressed, but have a real problem with my respirator. and I eventually reached him only because I was not ready to accept any answers that did not make sense to me.

I think that is why I can also function reasonably well with respiratory pressures that are 30% of normal, but can rapidly collapse and require emergent respiratory support, when they go even slightly lower.

another patient with the same degree of respiratory muscle involvment who is obese or has some stiffness of his chest wall, could have very different results and require different management.

I am telling you this just so that you understand how complex it is, and why it is so easy to go wrong and reach wrong conclussions, if one does not have a good understanding of the mechanics of breathing, or "cuts corners" when performing the tests.

it is also very different from an illness like ALS, where there is a constant and fixed weakness of the respiratory muscles, which is not as much effort dependent.

is there a pulmonologist that is supposed to review your test results?

is your neurologist going to see them as well?

at least you seem to be going in the right direction, even if with quite a lot of detours along the way.

alice